The invention relates to exercise devices.
It has been known in exercise to seek enhanced results by use of devices of the type consisting of a hollow body containing a dynamic volume of fluid. For example, Johnson U.S. Pat. No. 3,756,592 and U.S. Pat. No. 3,843,117 describe an exercise apparatus consisting of a hollow, rigid containing a fluent mass, e.g. sand, with handles and a method for use of such a device by women after child birth. Piccini U.S. Pat. No. 4,378,113 describes a similar device consisting of a hollow club into which a volume, e.g., of water is introduced and a method for use of the device by baseball players for warming-up wrists. Blome U.S. Pat. No. 4,659,078 describes a sling-like exercise device defining a flexible, fluid-filled enclosure for dynamically exercising muscles.